Cooling problems (overflow)

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3XV
Posts: 72
Joined: Sun Mar 05, 2017 6:09 am

Cooling problems (overflow)

#1 Post by 3XV » Sun Mar 04, 2018 2:27 pm

I drove my RD 500 with low RPM till 7000 at 4°C and the temperature was still 74-78 °C. :???:
After I drove her them with 10 000rpm the temperature went not down, only the coolant fluid run out.
Looks like too much pressure inside the system.
No thermostat assembled.
Assembled is GP radiator. They say 10-15% more cooling power.

I changed the coolant filling part and assembled one from Aprilia. Also 0.9 bar. Refilled the radiator.
Same problem.
I removed the water pipe at the water pump and radiator. Only 600ml water came out.
Does anybody knows something like this?
In the manual is written from 1.95 litre, but I was only able to fill in 1,5litre.
Is in wrong written in the manual, or something wrong with my RD? :-?
Or is based on the situation, that the lower cylinders are still filled with water?
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Linx
Posts: 169
Joined: Fri Jul 28, 2017 4:23 pm
Location: Stratford Upon Avon UK

Re: Cooling problems (overflow)

#2 Post by Linx » Sun Mar 04, 2018 2:32 pm

3XV wrote:I drove my RD 500 with low RPM till 7000 at 4°C and the temperature was still 74-78 °C. :???:
After I drove her them with 10 000rpm the temperature went not down, only the coolant fluid run out.
Looks like too much pressure inside the system.
No thermostat assembled.
Assembled is GP radiator. They say 10-15% more cooling power.

I changed the coolant filling part and assembled one from Aprilia. Also 0.9 bar. Refilled the radiator.
Same problem.
I removed the water pipe at the water pump and radiator. Only 600ml water came out.
Does anybody knows something like this?
In the manual is written from 1.95 litre, but I was only able to fill in 1,5litre.
Is in wrong written in the manual, or something wrong with my RD? :-?
Or is based on the situation, that the lower cylinders are still filled with water?
Could be your water pump seal has gone. Check for coolant in the gearbox oil.

Sent from my HTC Desire 530 using Tapatalk
:smt006 Current Bikes
1984 47X RD500LC, 2018 Triumph Speed Triple RS, 1999 Honda CB600F Hornet
Past Bikes Include
RD250LC, RD350YPVS LC2 Race Bike, RD350F2, 1976 CB400F

3XV
Posts: 72
Joined: Sun Mar 05, 2017 6:09 am

Re: Cooling problems (overflow)

#3 Post by 3XV » Sun Mar 04, 2018 3:39 pm

Hm,
sound at the first view not so logic. :smt017

If the sealing ring is defect, the pressure in the cooling system should be less.

But the water is flowing out at high rpm from the drain hose of the reservoir.
The smaller reservoir what I use gets over flooded after 500m at 10 000 rpm.

I think more about a defect cylinder head sealing. :-(
But I don´t like to disassemble the cylinder head, if it is not needed.

Linx
Posts: 169
Joined: Fri Jul 28, 2017 4:23 pm
Location: Stratford Upon Avon UK

Re: Cooling problems (overflow)

#4 Post by Linx » Sun Mar 04, 2018 3:47 pm

3XV wrote:Hm,
sound at the first view not so logic. :smt017

If the sealing ring is defect, the pressure in the cooling system should be less.

But the water is flowing out at high rpm from the drain hose of the reservoir.
The smaller reservoir what I use gets over flooded after 500m at 10 000 rpm.

I think more about a defect cylinder head sealing. :-(
But I don´t like to disassemble the cylinder head, if it is not needed.
Yes. With that extra information, it does sound like a head gasket has blown.

Sent from my HTC Desire 530 using Tapatalk
:smt006 Current Bikes
1984 47X RD500LC, 2018 Triumph Speed Triple RS, 1999 Honda CB600F Hornet
Past Bikes Include
RD250LC, RD350YPVS LC2 Race Bike, RD350F2, 1976 CB400F

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Speed Freak
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Location: Voitsberg, Austria

Re: Cooling problems (overflow)

#5 Post by Speed Freak » Sun Mar 04, 2018 4:53 pm

You can make a pressure test of the cooling system.

Apply some pressure to the system and wait - if the pressure drops you have a leak.
Check after the test if the crankcase is full of water (head gasket)
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

3XV
Posts: 72
Joined: Sun Mar 05, 2017 6:09 am

Re: Cooling problems (overflow)

#6 Post by 3XV » Mon Mar 05, 2018 12:38 pm

Thanks for the info,
but I do not have this tool.
And I´m also not a fan in filling my cylinder with water. :smt009

A manometer instead the radiator cap would be better to see, if overpressure will get produced.
I also do not have such a manometer.

So I need to remove the cylinder head. :cry:

But I´m still searching for somebody, who could give me the information about the water amount.

3XV
Posts: 72
Joined: Sun Mar 05, 2017 6:09 am

Re: Cooling problems (overflow)

#7 Post by 3XV » Tue Mar 06, 2018 2:58 pm

The cylinder head gasket is gone at the upper left cylinder. :roll:

Lucky me, no water in the cylinder. :grin:
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MK
Posts: 487
Joined: Thu Mar 09, 2006 12:54 pm
Location: Germany
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Re: Cooling problems (overflow)

#8 Post by MK » Tue Mar 06, 2018 3:55 pm

That looks like a crappy aftermarket gasket set.
The OEM Yamaha head gasket is black and expensive but it works.
Bye
Martin

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